I would. Bewitched is my first thought for both of those names (Tabitha moreso). That said, it's quite an old show, so I'd say go for it if you like the name. Just don't name your son Adam and you'll be fine.

I'd make the connection but it would be more of an, "Oh, I just noticed that," than anything. The names fit together to me because of the -tha and "heavy" A usage. It has nothing to do with the show Bewitched.